This invention relates to tote boxes and more particularly to tote boxes made from foldable box blanks and having self locking top rails to hold the blanks in an erected, assembled relationship.
Containers which are returnable/reusable are useful for the transportation, storage, and display of goods in commerce. Such containers, commonly called tote boxes, must be of sufficiently rigid construction to enable safe and damage free transport and storage of goods contained therein. These tote boxes are frequently designed so as to be stacked or mounted in a nesting relation for convenient transportation or storage of the tote boxes. In order to be stackable, the upper edge of the tote box is typically reinforced with a top rail or rim member which is adapted to receive another tote box stacked thereupon.
It is conventional to use a variety of materials for the construction of such tote boxes. Such materials typically consist of corrugated paperboard, corrugated plastic sheet, sheet metal and other such materials which are not sufficiently rigid to support a number of filled tote boxes in stacked relation. Therefore, it is also conventional to reinforce the corners of the tote boxes with structural supports so that a lower tote box of a stack of tote boxes can adequately support the load of the upper tote boxes and goods therein without deformation, possibly resulting in damage to the goods contained therein.
Typically these tote box corner supports and top rails require additional fasteners such as rivets, staples, screws or the like to secure the top rail and the corner support to the box itself. These fasteners add material costs and manufacturing steps to the construction of the tote box thereby resulting in an expensive and difficult to assemble tote box.
One patent which discloses a tote box having corner supports and a top rail which are not held in place with additional fasteners such as rivets, staples, screws or the like is applicants"" own U.S. Pat. No. 5,295,632. However, in both embodiments of tote box disclosed in this patent, the tote box blank must have end flaps in order to hold the corner supports in place. The use of end flaps requires additional material to form the box blank, resulting in additional cost to manufacture the tote box.
Accordingly, it is a primary objective of the present invention to provide a tote box made from a box blank, top rail and corner enhancers which facilitates assembly of the tote box without any fasteners and with a minimum of assembly steps and space.
Another objective of this invention has been to provide such a tote box which facilitates the stacking of additional tote boxes thereon without deformation of the tote box.
It is an additional objective of the present invention to provide a tote box corner enhancer which can be incorporated into the tote box with a minimum of assembly steps or operations, and which does not require additional fasteners to secure the corner enhancer to the walls of the tote box.
A further object of the present invention has been to reduce the amount of time and expense required to assemble a top edge and corner reinforced tote box.
The present invention is directed to a tote box which is assembled from a die cut box blank, at least one corner enhancer and a self-locking top rail. When folded into the appropriate shape, the die cut box blank results in a bottom, two opposed end walls, and two opposed side walls. The end walls and side walls have coplanar upper edges defining a top edge of the box. The erected end walls preferably have holes into which reinforcing hand holds may be inserted to aid in manual handling of a loaded tote box.
To hold the erected box blank in an assembled relationship and to reinforce the top edge of the tote box, a channel shaped top rail extends around the top edge of the tote box. This top rail has a downwardly open channel formed between a pair of channel side walls. This downwardly open channel is at a minimum approximately twice, and preferably three times, the thickness of the box blank. When the downwardly open channel of the top rail is pushed down over the top edge of the erected box blank, the channel fits over a double thickness of the tote box formed from tabs or flaps extending from the side and end walls of the box blank. The top rail is locked onto the top edge of the box as the result of an inwardly extending hook on the bottom of at least one channel side wall which snaps beneath downwardly folded tabs on the upper edges of at least two opposed side and end walls of the tote box.
The top rail is preferably manufactured from a single piece of extruded plastic or aluminum. However, the top rail may be constructed of other materials such as steel, for example. Preferably, the top rail is made of one piece of material having a pair of opposed ends. In order to create a generally rectangular top rail, the unitary piece of material is notched at four corners, folded at each corner notch and then the ends of the unitary piece of material are welded together to form the top rail which can then simply be snapped down over the erected tote box. Alternatively, the top rail may be constructed of multiple pieces of material welded or otherwise joined together. Preferably, the welds are at the corners of the top rail but may be located along the sides of the top rail. The inwardly extending hook on the bottom of at least one channel side wall engages the downwardly folded tabs thereby securing the top rail onto the top edge of the tote box without the need for further fasteners such as screws, rivets, or staples. The top rail preferably has a vertical lip which extends around the periphery of the top rail. The vertical lip enables nested stacking of additional tote boxes. A first or upper tote box may be nestably stacked on a second or lower tote box by placing the bottom of the first tote box within the vertical lip of the top rail of the second or lower tote box.
Structural corner enhancers reside at each corner of the tote box to hold the erected side and end walls together in an assembled relationship and to stiffen the tote box corners. The corner enhancers provide a load path for the weight of the stacked tote boxes and their contents to be distributed downwardly and thereby provide structural integrity to the tote box and prevent side and end wall deformation. Each corner enhancer has a first and second open leg channel, each open leg channel being formed between a pair of leg channel walls. Each of the open leg channels has a width of approximately the thickness of the box blank so that one of the end walls is frictionally held inside one of the open leg channels of a corner enhancer and one of the side walls is frictionally held inside the other open leg channel of the corner enhancer. In this manner, each corner enhancer functions to join together an end wall and a side wall in an orthogonal or right angle relationship. These corner enhancers hold the side and end walls of the box together, without the need for mechanical fasteners to secure the corner enhancers in place. Upon assembly, each corner enhancer has an upper portion which is located inside the downwardly open channel of the top rail.
In order to assemble the tote box of the present invention the die cut box blank is erected and the side and end walls of the erected box blank inserted into the open leg channels of the corner enhancers. A side edge of each side wall and a corresponding side edge of an adjacent end wall are located inside the open leg channels of each of the corner enhancers in order to hold and maintain the walls in an erect vertical position, orthogonal to each other. Once the box blank has been folded and the walls of the box blank inserted into the open leg channels of the corner enhancers at the corners of the box, the top rail is then snapped in place over the upper edges of the box walls and the upper portions of the corner enhancers.
In an alternative embodiment of the present invention, the tabs of the tote box do not extend downwardly from the upper edges of the box but rather are integrally formed from a pair of opposed side walls, a pair of opposed end walls or all four walls. In this embodiment, the tabs are located below the upper edge of the upper edges of the walls and are defined by cuts, at least portions of which are negative cuts, made in the box walls. Although one configuration of cut is illustrated and described, the cuts may assume many other configurations without departing from the spirit of the invention of this application. Once such cuts are made in the box blank, the tabs are pushed inwardly toward the center of the box. Due to the negative angle of at least a portion of the cut of each tab, the tab is maintained in an extended position and does not return to its original position. Thus, the negative angles on at least a portion of the tabs created by the angle of the cuts keep the tabs directed inwardly, thus providing a catching surface for the inwardly extending hook at the bottom of at least one channel side wall of the top rail. Tabs maintained in such an extended position ensure that the top rail will lock over the upper edges of the side and end walls.
In yet another alternative embodiment of the present invention, a pair of opposed side walls, a pair of opposed end walls or all four walls each have at least one opening therein. In this alternative embodiment, the openings are located below the upper edges of the walls and are defined by cuts made in the box walls. Although a generally rectangular configuration of opening is illustrated and described, the openings may assume many other configurations without departing from the spirit of the invention of this application. Clips are engaged with or secured to these openings. Each clip has at least one outwardly directed flange or projection. These flanges or projections provide catching surfaces for an inwardly extending hook of at least one channel side wall of the top rail or a groove formed in at least one channel side wall of the top rail. Although one configuration of clip is illustrated and described, the clips may assume many other configurations without departing from the spirit of the invention of this application. The top rail locks over the upper edges of the side and end walls via use of the clips.
One advantage of the present invention is that the tote box can be assembled rapidly without the need for intermediate fastener joining steps and without the need for multiple rivets or fasteners such as have been conventional in prior art tote boxes as, for example, in the tote box disclosed in the assignee""s own earlier U.S. Pat. No. 5,037,027. Another advantage of the present invention is that the stackable tote box may be constructed more quickly and less expensively than is presently possible in competitive type tote boxes.